1. Field of the Invention
This invention relates to a coloring structure which colors by reflection and interference of natural light and more particularly, to coloring fibers and tips used in a textile fabric, paint and so on.
2. Description of the Related Art
Recently, in a painting field for automobile, not only the conventional metallic painting using radiant materials of aluminum flakes but also a new painting using mica flakes, processed mica flakes or carbon fiber tips as the radiant materials have been worthy of notice in terms of an improvement in material feeling of painted surfaces and a fact to offer an anisotropically character thereto. Also in a field of an interior textile fabric, materials used in the above paintings and hues thereof have been taken seriously in terms of the improvement in material feeling.
In the former painting, however, the hue is gradually faded since paints containing pigments are gradually deteriorated by ultraviolet rays, infrared rays and so on, although the hue is also influenced by the radiant materials themselves contained in the paints. Also in the latter painting, a deterioration of paints and pigments used therein cannot be avoided at present.
In order to solve the above-mentioned problems, it has been studied a coloring structure which can generate colors by reflection and interference of the natural light without using coloring matters such as the paints and pigments etc. or which can generate deep and brilliant colors by a combination of the reflection and interference of the natural light with the paints or pigments contained the structure. For instance, Japanese Examined Patent Publication (Kokoku) No. 43-14185 discloses composite fibers to produce brilliance like a pearl by forming an overlapped-type of compound fiber consisting of more than two kinds of resins in different refractive Indexes. Furthermore, in documents of the society of textile manufacturing machine (vol. 42, No. 2, p. 55 and vol. 42, No. 10, p. 60; 1989), there are disclosed materials which can generate color by laminating an anisotropically molecular oriented film between two polarizing films.
However, in the above materials containing the anisotropically molecular oriented film, it is difficult to provide the materials in the form of thin fibers or small tips and to control a main wave length of light reflected by the materials. Therefore, it is not practical to use such materials for the coloring structure.
In Japanese Patent Publication Nos. 59-228042 (Kokai), 60-24847 (Kokoku) and 63-64535 (Kokoku), on the basis of a coloring structure of "Morpho" butterflies in South America, there are disclosed structures which can generate colors by the interference of natural light without using the normal pigments or paints. In addition, Japanese Patent Publication (Kokai) No. 62-170510 discolses a structure to generate an interfering color by arranging clearances of a constant width on surfaces of fibers in the structure.
However, since these publications do not teach the detailed specifications of the structures (ex. their thicknesses, lengths, refractive indexes of constituents etc.), it is impossible for those skilled in this art to manufacture a desired coloring structure on the basis of instructions disclosed in the publications.
Taking the above mentioned problems into consideration, we have already filed a coloring structure providing a brilliant hue which has never been obtained in the above-mentioned prior arts and which has few periodical changes in Japanese Patent Application Serial No. 4-172926.